Additionally, if you have any additional questions or comments, feel free to contact the Office of Jury Administration at (312) 603-JURY. To be eligible for jury service, you must be a citizen of the United States; at least 18 years old; a resident of the county; not have a pending lawsuit.If you have questions regarding your jury duty, call (618) 482-9148 and leave a message. This handbook is written to help you understand your duties as a grand juror, with some practical suggestions to assist you in carrying out those duties. The purpose of this booklet is to help you understand the things that happen and the terms that are used during a trial. If you are summoned again within this time period, simply call the Office of Jury Commission at (630) 553-4217 to be excused. If you are summoned again within this time period, simply call the Office of Jury Commission at (630) 553-4217 to be excused. If you received the Juror Qualification Questionnaire in the mail, it is a questionnaire, not a summons for jury service. Please be aware that forms will be displayed in a NEW browser window. (h) All juror's cards shall remain in the custody of the supervisor of jurors.